For months shops in United Kingdom have been flooded with any kind of Royal Wedding memorabilia (let's have a look in the gallery for food ones). The Centre for Retail Research estimates that souvenirs would account £222m of £515.5m forecast boost to retailers for the event.
On December 2010, Buckingham Palace published guidelines (often unheard) which production must observe. Commemoratives must be in good taste, free from any form of advertisement, carrying no implication of Royal custom or approval.
Royal guidelines are quite precise and detailed. They included: containers, coins and medallions, souvenirs and a bizarre constraints for textile: “With the exception of carpets, cushions, wall hangings and head scarves, Royal Devices MAY NOT be used on textiles (which includes articles of clothing, including T-shirts, drying up cloths and aprons).”
If an explanation or guidance is required in respect of the rules please write to the Lord Chamberlain’s Office, Buckingham Palace, London, SW1A 1AA.